The present invention relates generally to lighting fixtures and, more particularly, to lighting fixtures providing indirect light or luminance. Still more particularly, the present invention relates to variable focus indirect lighting fixtures.
Indirect lighting is widely recognized as the best type of lighting as it provides even illumination without the glare of direct illumination from the light source. Indirect lighting which resembles lumination from a skylight is the most desirable type of lighting. The benefit of indirect lighting is that the source of light, i.e., the point of lumination, is never visible. It is similar to the illumination received on a cloudy day where the sun is not visible. The lack of glare is one of the prime benefits of indirect lighting. The even distribution of the lighting is also a major benefit.
Indirect lighting through skylights can be focused on a specific area by the size of the skylight and the distance between the roof and the ceiling where the skylight is located. The ability to control indirect lighting to cover the space to be illuminated or the task area to be illuminated is not available through the use of commercially available lighting fixtures. Thus, there is a need in the art for an indirect lighting fixture control.
A prior approach to solving the problem of providing indirect lighting for indoor recessed lighting environments is a recessed, indirect lighting fixture, e.g., the Atrium fixture available from Eclairage Axis Lighting Inc. FIG. 1 is a perspective view of the recessed, indirect lighting fixture of the prior art.
A recessed, indirect lighting fixture 10 is mounted in a typical office environment ceiling 12. The ceiling 12 includes support beams 14 supporting ceiling panels 16 in a typical grid arrangement. These support beams 14 are normally suspended from an office space ceiling (not shown) via support wires (not shown). The lighting fixture 10 rests on, or is attached to, support beams 14 and fully covers an opening 15 in ceiling 12 of the same size as ceiling panel 16. Typical ceiling panel 16 dimensions are either two foot square or two feet by four feet.
The lighting fixture 10 includes a light source 18 mounted above ceiling 12 on opposite interior sides of the fixture 10 and substantially vertically aligned over the support beam 14. The light source 18, e.g., a fluorescent light tube, is partially surrounded by a channel 20, e.g., an aluminum extruded channel, extending coextensive with the opening 15 in the ceiling 12 for the fixture 10. The channel 20 is generally U-shaped and directs light from light source 18 toward a concave surface 21 formed by a curved reflector 22 forming a portion of the top surface of fixture 10.
Two curved reflectors 22 are joined together at common edges along a centerline of fixture 10 to form an upper side of the fixture. A single piece of material having two curved portions may be used in place of two separate pieces being joined. The transversely extending ends of the fixture 10 not having light source 18 have a substantially vertical end wall 24 connected to each of the curved reflectors 24 along a top edge and rest on, or are attached to, a transverse beam support 14a along a lower edge thereof.
Using the above-described lighting fixture 10, light is transmitted from light source 18 toward the concave surface 21 of curved reflector 22. The light reflects off concave surface 21 and passes through opening 15 to illuminate the office space below ceiling 12. As depicted in the side view of fixture 10 in FIG. 2, the angle of light distribution 26 using the recessed, indirect lighting fixture described above is approximately one hundred fifty (150) degrees. Thus, the fixture 10 provides a uniform light distribution over a large angle. However, there are many situations where a uniform distribution of light is needed only in a specific location, e.g., conference rooms, television studios, football or basketball arenas. In these situations, it is desirable to have more light on a specific subject or location, e.g., players on the basketball court or documents being read at a conference table, and fixture 10 is not able to focus the light as required. Therefore, there is a need in the art for a focussed indirect lighting fixture.
Further, certain applications of indirect lighting require different focus settings at different times. For instance, if a person is making a presentation in a conference room the lighting should be focussed on the presenter and the presentation, i.e., a narrow focus; however, if a discussion is occurring at the conference table, the lighting should be focussed on the table and any documents at the table, i.e., a broader focus. A typical solution for multiple levels of lighting focus is to use multiple differing light fixtures, e.g., recessed fluorescent lighting for a broader focus and incandescent directional lighting for narrow focus. Thus, there is a need in the art for a variable focus indirect lighting fixture.
The current practice in lighting is to use uplighting on suspended fixtures using the ceiling as the reflector. This practice is extremely inefficient and impractical and creates hot spots on the ceiling without controlling where the light is to be directed.
Current practice and currently available products on the market are all fixture designs with the lamps and reflectors being set with no adjustability or variation available either from the factory or in the field at the fixture. A field adjustable lighting fixture is particularly suited to television studios or video conferencing rooms. In television studios, the trend is toward the use of fluorescent lighting because such lighting provides a more uniform lumination lacking hot spots at a more comfortable cooler temperature, i.e., the person or persons under the light are not subjected to heat from the lights. The use of variable focus direct lighting fixtures has long been used in theater and television studios to control the beam spread of the luminaires.
Television studios have long used skrims or diffusers over either incandescent or fluorescent fixtures to soften the effect of the light source. Unfortunately, this has resulted in fires from the very hot incandescent lamps and a loss of light intensity when used with fluorescent lamps. A variable focus indirect lighting fixture would allow open aperture fixtures to efficiently disperse light over a controllable area with no glare and no direct light. Therefore, there is a need in the art for a variable focus indirect lighting fixture for use in television studios, video conference rooms, and theaters.
It is an object of the present invention to provide a variable focus indirect lighting fixture.
Another object of the present invention is to provide a variable focus indirect lighting fixture for use in television studios, video conference rooms, and theaters.
The above-described objects are achieved by a variable focus indirect lighting fixture. The lighting fixture has a pair of first reflectors with each reflector arranged to substantially surround a light source, and a second variable focus reflector positioned in front of the first reflectors. Each of the first reflectors has an opening arranged to direct lumination from the light source. The second reflector is positioned in front of each opening of the pair of first reflectors and arranged to receive and reflect the lumination from each light source passing through each opening of the pair of first reflectors. The second reflector has a pair of inner, concave surfaces arranged such that each inner surface faces a respective opening of the first reflectors and is arranged to receive and reflect the lumination from the respective light source passing through the opening of each of the first reflectors. The inner surfaces are aligned along a center line of the second reflector between the pair of first reflectors. The center line is adjustable to modify the concavity of the inner surfaces of the second reflector. Adjustment of the center line varies the focus of the light output reflected from the second reflector of the fixture.
In a method aspect, variable focussed indirect light is provided from a lighting fixture having at least one light source, a first reflector substantially surrounding the light source, and a second variable focus reflector positioned in front of the first reflector. The first reflector has an opening for directing the lumination from the light source and the second reflector is positioned in front of the opening of the first reflector to receive and reflect the lumination from the light source passing through the opening of the first reflector. The second reflector has an adjustable center point for raising and lowering the center point of the second reflector thereby adjusting the focus of lumination transmitted by the fixture. The center point of the second reflector is raised or lowered to adjust the focus of light transmitted from the fixture to an area to be illuminated.
Further, a lighting fixture apparatus is described as having a first reflector for substantially surrounding a light source, and a second variable focus reflector positioned in front of the first reflector. The first reflector has an opening arranged to direct lumination from the light source and the second reflector is arranged to receive and reflect the lumination from the light source passing through the opening of the first reflector. The second reflector has an inner, reflective, curved surface facing the opening of the first reflector and the second reflector has an adjustable center point arranged to modify the curvature of the second reflector to adjust the focus of light transmitted from the fixture to an area to be illuminated.
In an additional embodiment, the apparatus described above includes a pair of first reflectors surrounding a pair of light sources and the second reflector includes a pair of inner, reflective, curved surfaces for receiving and reflecting the lumination from the light source.
In a still further embodiment, the apparatus described above includes multiple first reflectors surrounding multiple light sources and the second reflector includes multiple inner, reflective, curved surfaces corresponding to the multiple first reflectors for receiving and reflecting the lumination from the light sources.
Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description thereof are to be regarded as illustrative in nature, and not as restrictive.